Nortel Circuit Card 311 Reference page 751

Figure 241
E and M Type I signaling patterns - originating party release on a tandem connection
Outgoing calls are processed as follows:
•
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.
— If answer supervision is provided by the far end, there is a change
from open to ground on the E lead (ground detection).
The M lead changes from ground to battery.
— If answer supervision is provided by the far-end, there is a change
from open to ground on the E lead (ground detection).
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Operation 751